1. Field of the Invention
This invention relates generally to a needle positioning attachment for sewing machines, and particularly to a needle positioning attachment which can be mounted on the main drive shaft of any industrial sewing machine, and the like, without major modification of the machine in order to control the position of a needle on the machine when the machine comes to a stop.
2. Description of the Prior Art
A basic difficulty encountered by the conventional industrial blind stitch sewing machine, and the like, is that each time the machine is stopped, the operator must reposition the needle prior to starting a new stitch. Conventionally, this needle repositioning is accomplished by the operator grasping the commonly provided handwheel of the machine and turning the wheel until the needle is in a desired position. This procedure results in a substantial loss of time, with a resulting loss in production.
It has been proposed to provide needle positioning devices on sewing machines in order to eliminate the necessity of carrying out the aforementioned needle positioning step prior to the start of each stitching operation on the machine. U.S. Pat. Nos. 2,277,475, issued Mar. 24, 1942, to S. B. Bilger, and 2,376,648, issued May 22, 1945, to T. A. Anderson, disclose examples of sewing machines provided with needle positioning attachments mounted on the main drive shaft of the machine. In these known constructions, however, the sewing machine must be suitably modified to receive the needle positioning device. U.S. Pat. Nos. 3,077,845, issued Feb. 19, 1963, to L. Bono, and 3,439,638, issued Apr. 22, 1969, to P. Zuk, disclose additional examples of automatic needle positioning devices for use with industrial sewing machines, and the like.